Gaseous conduction lamp electrode



July 7, 1931. F. scHAEFER ETAL 1,813,320

GSEOUS CONDUUTION LMP' ELECTBODE Filed Nov. 24, 1928 Patented July ".7, 1931 UNITED STATES PAT/ENT OFFICE g FRANK SCHAEFER, OF KALAMAZOO, AND ORA S. DUFFENDACK, 0F ANN ARBOR,

MICHIGAN; SAID DUFFENDAGK ASSIGNGR- TO AMERICAN SIGNS CORPORATION, OF

KALAMAZOO, MICHIGAN GAS'EOUS CONDUC'IION LAMP ELECTRODE Application led November 24, 1928.. Serial No. 321,606.

The main objects of this invention are:

First, to provide a method of making electrodes for gaseous conduction lamps which are not subject to sputtering or disintegration pin use, even when of relatively small size.

Second, to provide a method o-f making electrodes for gaseous tubelamps by means of which uniformity of results maybe had.

Third, to provide a method of making gaseous conduction lamps by means of which the parts may be very efficiently freed of occluded gases.

Objects pertaining todetails and economies of our improvements will appear from the description to follow. The invention is defined-'in the claims. y

The manner of carrying outl our improvements is illustrated in the accompanying drawings, in which:

Fig. 1 is /a fragmentary view of a gaseous tube lamp embodying our improvements.

Fig. 2 is a detailsection illustrating one of the steps of our improved method.

Fig. 3 is an illustration ofoa succeeding step, the parts being shown mainly conventionally. f

Fig. 4 is a det'ail viewof still another step, the parts also here being mainly shown conventionally.

Fig. 5 is an enlarged fragmentary view of the completed electrode.

Referring to the drawings, 1 represents a gaseous tube lamp and 2 one of the electrode chambers thereof. The electrode 3 'is arranged in this chamber and connected t the conduction wire 4.

The electrode 3, which is made in 'accordance with ,our improvements, consists of a body or base element 5, preferably a tubular foraminate screen formed of nickel. This screen is coated with or has incorporated therewith a metal of the alkaliV or alkaline earth groups such as barium, calcium and magnesium, preferably barium, which we have found very highly satisfactory. both from thev manufacturing standpoint and thel standpoint of the resulting product.

When barium is used barium carbonate is suspended in alcohol or melted paran and applied to the base 5- in the form of a coating shown at 6, Fig. 2. Either alcohol or paraimmay be employed as a vehicle but in any event it should be such as is capable of elimination by the application of heat, being either evaporated. or consumed by the heat.

or such portion'thereof as is desired, is comletely covered with Vthe barium oxide and arluln, a portion of the barium being intimately united with the base element.

It will be understood that Figs. 2 and 5 are not intendedr as accurate illustrations and that no'attempt has been made to showy the parts in proportions but it is believed these Ifigures will be helpful. f

The electrodes thus formed are then sealed within the tube 1 as shown by Fig. 4, the tube being connected to an exhausting pump 9. Heat is applied as by means of the induction heater 10- or othersuitable means to further heat the electrodes in vacuo, further converting the barium carbonate into barium l oxide and bariumand eliminating -the gases occluded in the electrodes.

The tube is also heated at this or a later stage to remove the occluded gases therefrom, after which operation thetube is ready to receive such gas or gases as are desired for its operation. j

The barium oxide-barium mixture adheres to the surface of the base metal in the form of a porous or spongy or granular layer. The composition and structure of this layer when formed as described above is such that it is not subject to serious disintegration when used as an electrode in gaseous conduction lamps even when the electrodes are of rela-- tively small area.

We are able to produce electrodes of very uniform quality and to effectively remove the occluded gases therefrom. n p Lamps made in accordance with our im proved method and embodying our improved 5 electrodes are 'economical to produce and are of long life.

Having thus described our invention what We claim as nevv and desire to secure by Letters Patent, is: v

1. The method of making electrodes .for

gaseous conduction lamps consistin of applying barium carbonate to a nickel ase element, and heating in an oxidizing atmosphere by subjecting to an impingingvflame until a substantial portion of the barium carbonate is converted to barium oxide and fused with a portion of the base element into a homogeneous substance.

2. The method of making electrodes for gaseous conduction lamps consisting of ap,-

plying an alkaline metal compound to a base element, and heating in an oxidizing atmosphere until a portion. of the base element is oxidized and fused With the alkaline earth metal into a homogeneous substance.

3. The method of making electrodes for gaseous conduction lamps consisting of ap-y plying an alkaline earth metal compound to a base element, and heating in an oxidizing atmosphere until a portion of the base element and the alkaline earth metal compound is oxidized and fused into a homogeneous substance.-

4. The method of making electrodes for gaseous conduction lamps consisting of applying an alkaline earth metal compound to a metal'base element, and heating in an oxidizing atmosphere by subjecting to an impinging flame until av portion of the base 40 element and the alkaline earth metal compound is oxidized and fused into a, homogeneous substance.

In Witness whereof We have hereunto set our hands.

FRANK SCHAEFER.

ORA S. DUFFENDACK. 

